1. Technical Field of The Invention
The present invention relates to a tire for an industrial vehicle such as forklift truck, and more particularly, a cushion tire formed from a rubber material without forming any airspace inside the tire to thereby prevent a fear of blowouts.
2. Description of Prior Art
In an industrial vehicle such as forklift truck having a conventional structure, a large load is applied at a time of running at a low speed, and accordingly, in these days, a cushion tire formed from a rubber material, which has no inside airspace for preventing a fear of blowouts, has been widely utilized.
As such a cushion tire, a pneumatic type cushion tire and a press-on type cushion tire have been generally known. The pneumatic type cushion tire has a double-layer structure, as shown in a sectional view of a tire of FIG. 15, in which a tread rubber layer 1 is disposed at an outer circumferential side of the tire and a base rubber layer 2 is disposed at an inner circumferential side, and an aspect ratio, which is the ratio of the tire sectional height with respect to the tire width, is set to 95 to 120%. An outer appearance of the tire shown in FIG. 15 provides almost the same shape as that of a pneumatic tire so that the tire can be durable against a large load while making riding feeling comfortable at the vehicle running time.
Further, the press-on type cushion tire has a structure, as shown by a sectional view of FIG. 16, in which a tread rubber layer 1 is disposed at the outer circumferential side of the tire and a steel-made base band 12 is disposed at the inner circumferential side so that the tread rubber layer 1 is fixed to the base band 12, and an aspect ratio, which is the ratio of the tire sectional height to the tire width, is made to be lower than that of the abovementioned pneumatic type cushion tire.
The former pneumatic type cushion tire has a double structure provided with the tread rubber layer and the base rubber layer, and the aspect ratio, which is the ratio of the tire sectional height with respect to the tire width, is set to be high to 95 to 120%, so that a wheel, to which such pneumatic type cushion tire is fitted, becomes small in diameter, and accordingly, the inner circumferential space of the wheel hence becomes small. Therefore, only a small-sized brake can be housed in this inner circumferential space, resulting in a problem of reducing a braking performance of the industrial vehicle.
On the other hand, in the latter press-on type cushion tire, since the aspect ratio, which is the ratio of the tire sectional height to the tire width, is made lower than that of the former pneumatic type cushion tire, the inner circumferential space of a wheel to which the press-on type cushion tire is fitted can be made large, so that a large-sized brake can be installed in the inner circumferential space and the brake performance can be hence improved. However, the spring constant increases due to the low aspect ratio, the unevenness in the running road surface is directly transmitted to a vehicle's driver, and the riding feeling becomes extremely uncomfortable at the vehicle running time.